diff -r b273b43b16d2 -r 8354b390f1a2 qmlfrontend/engine_interface.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/qmlfrontend/engine_interface.h	Wed Nov 07 15:59:51 2018 +0100
@@ -0,0 +1,36 @@
+#ifndef ENGINE_H
+#define ENGINE_H
+
+#include <stdint.h>
+
+#ifdef __cplusplus
+namespace Engine {
+extern "C" {
+#endif
+
+typedef struct _EngineInstance EngineInstance;
+
+typedef struct {
+  uint32_t width;
+  uint32_t height;
+  uint8_t hedgehogs_number;
+  unsigned char* land;
+} PreviewInfo;
+
+typedef uint32_t protocol_version_t();
+typedef EngineInstance* start_engine_t();
+typedef void generate_preview_t(EngineInstance* engine_state,
+                                PreviewInfo* preview);
+typedef void cleanup_t(EngineInstance* engine_state);
+
+extern protocol_version_t* protocol_version;
+extern start_engine_t* start_engine;
+extern generate_preview_t* generate_preview;
+extern cleanup_t* cleanup;
+
+#ifdef __cplusplus
+}
+};
+#endif
+
+#endif  // ENGINE_H